ABSTRACT
This chapter presents a selection of 39 orders and 113 families following most of the recommendations of the latest classification published to date. Each order is succinctly summarized and accompanied where needed by a key to families. The order comprises families with imperfect ovules—i.e., with imperfect integuments and sometimes submerged in the placenta—the representatives of which are more or less parasites. The Rosales, as defined by molecular systematics, encompass mostly families with floral reductions. Mostly ligneous plants characterized by internal phloem, extra-floral myrmecophilous organs, simple opposite leaves, and heterochlamydeous, dialypetalous, perigynous or epigynous flowers with a polymerous or dimerous androecium. The monotypic family Aquifoliaceae has often changed affiliation: linked to Celastrales by many conventional systems, it has more recently been connected to Cornales by Dahlgren and to Theales by Thome.
